The present invention relates to an apparatus for fine pattern formation, a process for producing fine nozzles, and a method for fine pattern formation, and particularly to an apparatus for fine pattern formation, which can be applied, for example, to pattern formation for the production of liquid crystal displays, plasma displays, and flat displays of electroluminescence or the like, and conductor pattern formation and correction of conductor patterns of printed wiring boards, a process for producing fine nozzles used in the apparatus for fine pattern formation, and a method for the fine pattern formation.
Fine patterns, for example, for color filters for liquid crystal displays have been formed by photolithography, printing, electrodeposition, or the like. Among these pattern formation methods, photolithography is advantageous in accuracy and quality of appearance. The photolithography, which can realize wiring of a pattern with high accuracy, is also used in the formation of conductor patterns in printed wiring boards.
In an example of the production of a color filter by photolithography, a photosensitive resist is coated on a thin film of a metal, such as chromium, formed, for example, by sputtering or vapor deposition, exposure through a photomask and development are carried out to prepare a resist pattern, and the thin metal film is patterned by etching using the resist pattern as a mask to form a black matrix. Next, a color pigment-containing photosensitive resist is coated, followed by exposure through a photomask and development to form a colored layer for a color filter. On the other hand, in the case of a printed wiring board, a photosensitive resist pattern is formed on a copper plating, and the copper plating is etched using the photosensitive resist pattern as a mask to produce a conductor pattern.
The above-described conventional fine pattern formation by photolithography, such as pattern formation for a color filter and conductor pattern formation, however, disadvantageously suffers from a complicated process, which is an obstacle to a reduction in production cost.
Under the above circumstances, the present invention has been made, and it is an object of the present invention to provide an apparatus for fine pattern formation, which can form a fine pattern with high accuracy by direct writing of a pattern with ink, a production process of fine nozzles provided in the apparatus for fine pattern formation, and a method for fine pattern formation.
In order to attain the above object, according to one aspect of the present invention, there is provided an apparatus for fine pattern formation comprising: a silicon substrate; a plurality of fine holes which extend through the silicon substrate from the surface of the silicon substrate to the back surface of the silicon substrate and have a silicon oxide layer on the wall surface thereof; fine nozzles which are protruded, integrally with the silicon oxide layer, on the back surface side of the silicon substrate from each opening of the fine holes; a silicon nitride layer provided on the surface and side of the silicon substrate; a support member provided on the surface side of the silicon substrate; an ink passage for supplying ink to the opening of each fine hole on the surface side of the silicon substrate; and an ink supplying device connected to the ink passage.
In this apparatus, preferably, the diameter of the openings in the fine nozzles is in the range of 1 to 100 xcexcm in a variation within xc2x11 xcexcm and the fine nozzles are provided at a pitch in the range of 2 to 1000 xcexcm.
According to another aspect of the present invention, there is provided an apparatus for fine pattern formation, comprising: a silicon substrate; a plurality of fine nozzles protruded from the back surface of the silicon substrate; a plurality of fine holes which extend at fine nozzle formed sites through the silicon substrate from the surface of the silicon substrate to the back surface of the silicon substrate and have a silicon oxide layer on the wall surface thereof; a support member provided on the surface side of the silicon substrate; an ink passage for supplying ink to the opening of each fine hole on the surface side of the silicon substrate; and an ink supplying device connected to the ink passage, said fine nozzles each comprising a nozzle base provided integrally with the silicon substrate, an inner surface layer of silicon oxide provided on the inner wall surface of nozzle bases in communication with the fine holes, and an end face layer of silicon oxide provided integrally with the inner surface layer of silicon oxide so as to cover the front end face of the nozzle bases.
In this apparatus, preferably, the diameter of the openings in the fine nozzles is in the range of 1 to 100 xcexcm in a variation within xc2x11 xcexcm and the fine nozzles are provided at a pitch in the range of 4 to 1000 xcexcm.
In the above apparatuses for fine pattern formation, preferably, the protrusion length of the fine nozzles is in the range of 1 to 150 xcexcm.
In the above apparatuses for fine pattern formation, preferably, the fine holes in their openings on the surface side of the silicon substrate are in the form of tapered concaves which have been widened toward the surface side of the silicon substrate. Alternatively, in the above apparatuses for fine pattern formation, preferably, the fine holes in their openings on the surface side of the silicon substrate are in the form of multistaged concaves which have been widened toward the surface side of the silicon substrate.
In the above apparatuses for fine pattern formation, preferably, fine holes are divided into two or more groups and ink passages are provided separately from each other or one another for respective fine hole groups.
According to still another aspect of the present invention, there is provided a process for producing a plurality of fine nozzles, formed of silicon oxide, protruded from one surface of a silicon substrate and in communication with fine holes which extend through the silicon substrate and have a silicon oxide layer on the wall surface thereof, said process comprising: a first step of providing a silicon substrate having on its whole surface a silicon nitride layer and forming a mask pattern having a plurality of fine openings on the silicon nitride layer in its portion located on one surface of the silicon substrate; a second step of forming through fine holes in the silicon substrate by deep etching using the mask pattern as a mask; a third step of removing the mask pattern and oxidizing the inside of the through fine holes of the silicon substrate to form a silicon oxide layer; and a fourth step of removing a part of the silicon nitride layer and a part of the silicon substrate from one surface of the silicon substrate by dry etching to expose the silicon oxide layer by a predetermined length, thereby forming fine nozzles.
In the fourth step, preferably, etching is started with the surface from which the mask pattern has been removed.
According to a further aspect of the present invention, there is provided a process for producing a plurality of fine nozzles protruded from one surface of a silicon substrate, said fine nozzles comprising a nozzle base, provided integrally with the silicon substrate, and a silicon oxide end face layer covering the front end face of the nozzle base, said nozzle base being in communication with fine holes, which extend through the silicon substrate and have a silicon oxide layer on the wall surface thereof, and having a silicon oxide inner surface layer on its inner wall surface, said process comprising: a first step of providing a silicon substrate having on its whole surface a silicon nitride layer and patterning the silicon nitride layer in its portion located on one surface of the silicon substrate to form a pattern having a plurality of small openings; a second step of forming a mask thin film so as to cover the pattern of the silicon nitride layer and patterning the mask thin film to form a mask pattern having fine openings located within the small openings; a third step of forming through fine holes in the silicon substrate by deep etching using the mask pattern as a mask; a fourth step of removing the mask pattern and oxidizing sites within the through fine holes in the silicone substrate and sites exposed within the small openings to form a silicon oxide layer; a fifth step of removing the silicon nitride layer and removing a part of the silicon substrate by dry etching using the silicon oxide layer as a mask from the surface side, on which the silicon oxide layer has been formed, to form nozzle bases having a predetermined length, thereby forming fine nozzles.
According to a still further aspect of the present invention, there is provided a process for producing a plurality of fine nozzles, formed of silicon oxide, protruded from one surface of a silicon substrate and in communication with fine holes which extend through the silicon substrate and have a silicon oxide layer on the wall surface thereof, said process comprising: a first step of providing a silicon substrate of  less than 100 greater than  surface crystal orientation having on its whole surface a silicon nitride layer and patterning the silicon nitride layer in its portion located on one surface side of the silicon substrate to form a pattern having a plurality of openings for taper; a second step of etching the surface of the silicon substrate by crystallographically anisotropic etching using the silicon nitride layer as a mask to form tapered concaves; a third step of forming a mask thin film on both surfaces of the silicon substrate and patterning the mask thin film in its portion located on the surface of the silicon substrate remote from the tapered concaves to form a mask pattern having fine openings such that the center of each opening substantially conforms to the center of each tapered concave through the silicon substrate; a fourth step of forming through fine holes in the silicon substrate by deep etching using, as a mask, the mask pattern and the mask thin film; a fifth step of removing the mask pattern and the mask thin film and oxidizing sites within the through fine holes in the silicone substrate and sites exposed within the tapered concaves to form a silicon oxide layer; and a sixth step of removing a part of the silicon nitride layer and a part of the silicon substrate by dry etching from the surface side of the silicon substrate remote from the tapered concaves to expose the silicon oxide layer by a predetermined length, thereby forming fine nozzles.
According to another aspect of the present invention, there is provided a process for producing a plurality of fine nozzles protruded from one surface of a silicon substrate, said fine nozzles comprising a nozzle base, provided integrally with the silicon substrate, and a silicon oxide end face layer covering the front end face of the nozzle base, said nozzle base being in communication with fine holes, which extend through the silicon substrate and have a silicon oxide layer on the wall surface thereof, and having a silicon oxide inner surface layer on its inner wall surface, said process comprising: a first step of providing a silicon substrate of  less than 100 greater than  surface crystal orientation having on its whole surface a silicon nitride layer and patterning the silicon nitride layer in its portion located on one surface side of the silicon substrate to form a pattern having a plurality of openings for taper; a second step of etching the surface of the silicon substrate by crystallographically anisotropic etching using the silicon nitride layer as a mask to form tapered concaves; a third step of patterning the silicon nitride layer in its portion located on the surface side of the silicon substrate remote from the tapered concaves to form a pattern having small openings such that the center of each opening substantially conforms to the center of each tapered concave through the silicon substrate; a fourth step of forming a mask thin film on both surfaces of the silicon substrate and patterning the mask thin film in its portion located on the surface side of the silicon substrate remote from tapered concaves to form a mask pattern having fine openings located within the small openings; a fifth step of forming through fine holes in the silicon substrate by deep etching using, as a mask, the mask pattern and the mask thin film; a sixth step of removing the mask pattern and the mask thin film and oxidizing sites within the through fine holes in the silicone substrate, sites exposed within the small openings, and sites exposed within the tapered concaves to form a silicon oxide layer; and a seventh step of removing the silicon nitride layer and removing a part of the silicon substrate by dry etching using the silicon oxide layer as a mask from the surface side of the silicon substrate remote from the tapered concaves to form nozzle bases having a predetermined length, thereby forming fine nozzles.
According to still another aspect of the present invention, there is provided a process for producing a plurality of fine nozzles, formed of silicon oxide, protruded from one surface of a silicon substrate and in communication with fine holes which extend through the silicon substrate and have a silicon oxide layer on the wall surface thereof, said process comprising: a first step of providing a silicon substrate having on its whole surface a silicon nitride layer, forming a mask pattern having a plurality of fine openings on the silicon nitride layer in its portion located on one surface of the silicon substrate, and forming, on the silicon nitride layer on the other surface of the silicon substrate, a mask pattern having wide openings such that the center of each wide opening substantially conforms to the center of each fine opening through the silicon substrate; a second step of forming fine holes having predetermined depth in the silicon substrate by deep etching using the mask pattern having fine openings as a mask; a third step of forming wide concaves in the silicon substrate by deep etching using the mask pattern having wide openings as a mask in such a manner that the openings of the fine holes are exposed within the wide concaves, thereby forming multistaged concaves; a fourth step of removing the mask pattern and oxidizing sites within the fine holes of the silicon substrate and sites exposed within the wide concaves to form a silicon oxide layer; and a fifth step of removing a part of the silicon nitride layer and a part of the silicon substrate from the surface of the silicon substrate remote from the wide concaves by dry etching to expose the silicon oxide layer by a predetermined length, thereby forming fine nozzles.
According to a further aspect of the present invention, there is provided a process for producing a plurality of fine nozzles protruded from one surface of a silicon substrate, said fine nozzles comprising a nozzle base, provided integrally with the silicon substrate, and a silicon oxide end face layer covering the front end face of the nozzle base, said nozzle base being in communication with fine holes, which extend through the silicon substrate and have a silicon oxide layer on the wall surface thereof, and having a silicon oxide inner surface layer on its inner wall surface, said process comprising: a first step of providing a silicon substrate having on its whole surface a silicon nitride layer and patterning the silicon nitride layer in its portion located on one surface of the silicon substrate to form a pattern having a plurality of small openings; a second step of forming a mask thin film so as to cover the pattern of the silicon nitride layer and then patterning the mask thin film to form a mask pattern having fine openings located within the small openings, and, in addition, patterning the mask thin film on the other surface to form a mask pattern having wide openings such that the center of each wide opening substantially conforms to the center of each fine opening through the silicon substrate; a third step of forming fine holes having predetermined depth in the silicon substrate by deep etching using the mask pattern having fine openings as a mask; a fourth step of forming wide concaves in the silicon substrate by deep etching using the mask pattern having wide openings as a mask in such a manner that the openings of the fine holes are exposed within the wide concaves, thereby forming multistaged concaves; a fifth step of removing the mask pattern and oxidizing sites within the fine holes of the silicon substrate, sites exposed within the wide concaves, and sites exposed within the small openings to form a silicon oxide layer; and a sixth step of removing the silicon nitride layer and removing a part of the silicon substrate by dry etching using the silicon oxide layer as a mask from the surface of the silicon substrate remote from the wide concaves to form nozzle bases having a predetermined length, thereby forming fine nozzles.
According to the above invention, ink supplied to the fine holes in the silicon substrate can be ejected through the fine nozzles and deposited onto a pattern object to directly write a pattern on the pattern object, and the amount of ink deposited can be varied as desired by varying the amount of ink supplied.
Furthermore, in order to attain the above object, according to a further aspect of the present invention, there is provided an apparatus for fine pattern formation comprising: a silicon substrate; a plurality of fine holes which extend through the silicon substrate from the surface of the silicon substrate to the back surface of the silicon substrate and have a silicon oxide layer on the wall surface thereof; fine nozzles which are protruded, integrally with the silicon oxide layer, on the back surface side of the silicon substrate from each opening of the fine holes; a reinforcing layer provided at least on the front end face and outer face of the fine nozzles; a support member provided on the surface side of the silicon substrate; an ink passage for supplying ink to the opening of each fine hole on the surface side of the silicon substrate; and an ink supplying device connected to the ink passage.
In the above apparatus for fine pattern formation, preferably, the thickness of the reinforcing layer is at least twice the thickness of the fine nozzles.
In the above apparatus for fine pattern formation, preferably, the reinforcing layer is formed of any one of silicon oxide and phosphorus silicon glass.
In the above apparatus for fine pattern formation, preferably, the fine nozzles have an opening diameter in the range of 1 to 100 xcexcm and are provided at a pitch in the range of 4 to 1000 xcexcm. Alternatively, in the above apparatus for fine pattern formation, preferably, the fine nozzles have a projection length in the range of 1 to 400 xcexcm.
In the above apparatus for fine pattern formation, preferably, the fine holes in their openings on the surface side of the silicon substrate are in the form of tapered concaves which have been widened toward the surface side of the silicon substrate. Alternatively, in the above apparatus for fine pattern formation, preferably, the fine holes in their openings on the surface side of the silicon substrate are in the form of multistaged concaves which have been widened toward the surface side of the silicon substrate.
In the above apparatus for fine pattern formation, preferably, the fine holes are divided into two or more groups and ink passages are provided separately from each other or one another for respective fine hole groups.
In the above apparatus for fine pattern formation, preferably, a water-repellent layer is provided at least on the reinforcing layer, which is provided on the outer face of the fine nozzles, and on the back surface side of the silicon substrate.
In the above apparatus for fine pattern formation, preferably, the water-repellent layer is formed of fluorocarbon.
According to the present invention, the provision of the reinforcing layer in the fine nozzles can enhance the mechanical strength of the fine nozzles, ink supplied to the fine holes in the silicon substrate can be ejected through the fine nozzles and deposited on the pattern object to directly write a pattern, and the amount of ink deposited can be varied as desired by varying the amount of ink supplied.
Further, in order to attain the above object, according to another aspect of the present invention, there is provided an apparatus for fine pattern formation, comprising: a silicon substrate; a plurality of fine holes provided so as to extend through the silicon substrate from the surface of the silicon substrate to the back surface of the silicon substrate; a main electrode provided on the surface side of the silicon substrate; a counter electrode provided on the back surface side of the silicon substrate while leaving a predetermined space between the main electrode and the counter electrode; a support member provided on the surface side of the silicon substrate; an ink passage for supplying ink to openings in the fine holes on the surface side of the silicon substrate; and an ink supplying device connected to the ink passage.
In the above apparatus for fine pattern formation, preferably, nozzles are protruded from the openings of the fine holes on the back surface side of the silicon substrate.
In the above apparatus for fine pattern formation, preferably, the wall surface of the fine holes has a silicon oxide layer and the nozzles are formed of silicon oxide.
In the above apparatus for fine pattern formation, preferably, the counter electrode is in a drum or flat plate form.
In the above apparatus for fine pattern formation, preferably, the fine holes have an opening diameter in the range of 1 to 100 xcexcm and are provided at a pitch in the range of 2 to 1000 xcexcm.
In the above apparatus for fine pattern formation, preferably, the nozzles have a protrusion length in the range of 10 to 400 xcexcm.
In the above apparatus for fine pattern formation, preferably, the fine holes in their openings on the surface side of the silicon substrate are in the form of tapered concaves which have been widened toward the surface side of the silicon substrate. Alternatively, in the above apparatus for fine pattern formation, preferably, the fine holes in their openings on the surface side of the silicon substrate are in the form of multistaged concaves which have been widened toward the surface side of the silicon substrate.
In the above apparatus for fine pattern formation, preferably, the fine holes are divided into two or more groups and ink passages are provided separately from each other or one another for respective fine hole groups. Alternatively, in the above apparatus for fine pattern formation, preferably, main electrodes are separately provided for respective fine hole groups.
According to still another aspect of the present invention, there is provided a method for fine pattern formation, comprising the step of: while relatively scanning any one of the apparatuses for fine pattern formation and a pattern object in a predetermined direction, continuously or intermittently ejecting ink supplied at low pressure from the ink passage onto the pattern object through the fine holes in such a state that a voltage is applied to the main electrode in the apparatus for fine pattern formation, whereby a stripe pattern or a dot pattern is formed.
In the above method for fine pattern formation, preferably, stripes constituting the pattern are formed by supplying ink through a plurality of fine holes arranged on an identical line along the scanning direction.
According to a further aspect of the present invention, there is provided a method for fine pattern formation, comprising the steps of: disposing any one of the above apparatuses for fine pattern formation at a predetermined position of a pattern object; and ejecting a given amount of ink supplied at low pressure from the ink passage onto the pattern object through the fine holes in such a state that a voltage is applied to the main electrode of the apparatus for fine pattern formation, whereby a pattern is formed.
In the above method for fine pattern formation, preferably, the voltage applied to the main electrode is regulated to control ink ejection width and the amount of ink ejected.
According to the present invention, supplied ink can be ejected through the fine holes in the silicon substrate by an electric field formed between the main electrode and the counter electrode and a low pressure applied at the time of supply of the ink and can be deposited onto a pattern object to directly write a pattern, and the amount of ink deposited can be varied as desired by varying the field strength and the ink supply pressure to control ink ejection width and the amount of ink ejected. As used herein, the term xe2x80x9cinkxe2x80x9d generally refers to a liquid composition comprising a colorant, such as a dye or a pigment, and a binder or a vehicle. For example, in display members or circuit formation applications, however, the ink widely embraces pastes containing metallic or magnetic fine particles or ceramic or other fine particles, and liquid compositions containing a resin or a phosphor material or an organic EL material, and photoresists.